Born in the poor Southeast Federal District of Earth, Reyes was denied access to formal education. Yet, the idea of exploring distant stars provided the only hope of escape from his harsh home life, and is what constantly drove him onward. At the age of 16, Reyes eagerly enlisted for Armored Infantry selection.

His imposing size served him well and he was quickly assigned as a Squad Gunner to 9th Platoon, 8th Armored Infantry where he quickly gained the reputation for being a quiet, no-nonsense, and generally good-hearted man who lets his guns do the talking.

Reyes first served in the Outer Rim War, where he first arrived alongside fellow squadmate Graves, as a replacement for a nearly destroyed 1st Recon Platoon. He served with distinction throughout the war, most notably taking in the final battle of the Outer Rim War, which resulted in the death of Commander Soren, leader of the enemy Arm of Orion, and the near dissolution of the Arm itself.

Strangely, Reyes was not heavily involved in the events of the Spear Crisis, despite being a dedicated member of the elite 1st Recon Platoon. It is likely that he stayed behind in Fort Solomon to supervise the training of new recruits on planet Atlas.